U.S. patent number 4,700,912 [Application Number 06/855,303] was granted by the patent office on 1987-10-20 for laser illumination system for aircraft launch and landing system.
This patent grant is currently assigned to Grumman Aerospace Corporation. Invention is credited to Marshall J. Corbett.
United States Patent |
4,700,912 |
Corbett |
October 20, 1987 |
**Please see images for:
( Certificate of Correction ) ** |
Laser illumination system for aircraft launch and landing
system
Abstract
A giant column of air is employed to assist in the vertical
take-off and landing of an aircraft. The column of air is forced
through movable louvers which steer the aircraft on the air column.
A pressure differential occurs on top of the air column so as to
center an aircraft on the air column. In order to illuminate the
air column, a salt spray is introduced into the column and a laser
source resonates the crystals of the salt thereby causing energy to
be radiated from the column which may be detected and displayed by
an approaching aircraft.
Inventors: |
Corbett; Marshall J. (East
Northport, NY) |
Assignee: |
Grumman Aerospace Corporation
(Bethpage, NY)
|
Family
ID: |
25320903 |
Appl.
No.: |
06/855,303 |
Filed: |
April 24, 1986 |
Current U.S.
Class: |
244/63; 244/110E;
244/114R |
Current CPC
Class: |
B64F
1/20 (20130101); B64F 1/00 (20130101) |
Current International
Class: |
B64F
1/20 (20060101); B64F 1/00 (20060101); B64F
001/00 () |
Field of
Search: |
;244/63,11E,114R,114B,1R
;455/609,610,611 ;430/945 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
1164245 |
|
Feb 1964 |
|
DE |
|
2506974 |
|
Sep 1976 |
|
DE |
|
2514148 |
|
Apr 1983 |
|
FR |
|
868342 |
|
May 1961 |
|
GB |
|
Other References
"Northrop Using Argon Laser To Measure Vortex Flow, " Aviation
Week, Jul. 29, 1985, p. 66..
|
Primary Examiner: Peters, Jr.; Joseph F.
Assistant Examiner: Corl; Rodney
Attorney, Agent or Firm: Pollock, VandeSande &
Priddy
Claims
I claim:
1. In a system for assisting an aircraft to vertically take off and
land in a preselected area, the system having:
means for generating a column of air having a centrally depressed
pressure distribution across the top thereof for capturing an
aircraft on the column;
means for controlling the height of the column thereby enabling an
aircraft to be raised or lowered to the preselected area by the air
column;
a column illuminator comprising:
means for seeding the air column with a crystalline material;
and
means for causing resonant excitation of the crystalline material
thereby radiating detectable energy from the column which defines
the column boundaries.
2. The structure set forth in claim 1 wherein the seeding means
comprises means for introducing a salt solution spray into the
column.
3. In a system for assisting an aircraft to vertically take off and
land in a preselected area, the system having:
means for generating a column of air having a centrally depressed
pressure distribution across the top thereof for capturing aircraft
on the column;
means for controlling the height of the column thereby enabling an
aircraft to be raised or lowered to the preselected area by the air
column;
a column illuminator comprising:
means for seeding the air column with a crystalline material;
and
means for causing resonant exicitation of the crystalline material
thereby radiating detectable energy from the column which defines
the column boundaries;
wherein the means for causing resonant excitation of the material
includes a laser light source.
4. In a system for assisting an aircraft to vertically take off and
land in a preselected area, the system having:
means for generating a column of air having a centrally depressed
pressure distribution across the top thereof for capturing aircraft
on the column;
means for controlling the height of the column thereby enabling an
aircraft to be raised or lowered to the preselected area by the air
column;
a column illuminator comprising:
means for seeding the air column with a crystalline material;
and
means for causing resonant excitation of the crystalline material
thereby radiating detectable energy from the column which defines
the column boundaries;
wherein the means for causing resonant excitation of the material
includes a laser light source;
and further wherein the seeding means comprises means for
introducing a salt solution spray into the column.
5. In a shipboard-based landing and take-off system for aircraft,
the system including:
at least one fan located within the deck of the ship for generating
an upwardly directed air column having a centrally depressed
pressure distribution across the top thereof for capturing an
aircraft on the column;
vent means located in the ship for supplying air and saltspray to
the fans;
movable louvers located above the fans for steering the air column
to compensate for ship roll;
a grid located above the louvers for supporting an aircraft thereon
prior to take-off and after landing;
a column illuminator comprising a laser directed toward the column
for causing resonance of salt crystals in the column thereby
radiating detectable energy from the column and defining the
boundaries of the latter.
6. The structure set forth in claim 5 wherein an aircraft is
outfitted with means for detecting the radiated energy from the
column and displaying an output thereof.
7. In a method for effecting vertical take-off and landing of an
aircraft on board a ship including the steps:
generating a vertical air column above the deck of the ship;
creating a centrally depressed pressure distribution across the top
of the air column for capturing an aircraft thereon;
controlling the height of the column thereby enabling an aircraft
to be raised or lowered to the deck by the air column:
illuminating the column comprising the steps:
seeding the air column with a crystalline material; and
causing a resonant excitation of the crystalline material thereby
radiating detectable energy from the column which defines the
column boundaries.
8. The method set forth in claim 7 wherein the seeding step is
accomplished by introducing salt solution spray into the
column.
9. The method set forth in claim 8 together with the steps of:
detecting the energy radiated from the column; and
displaying the radiated energy thereby defining the boundary of the
column.
10. The method of claim 7 wherein the step of causing resonant
excitation includes the use of a laser directed toward the column.
Description
FIELD OF THE INVENTION
The present invention relates to aircraft launch and landing
systems, and more particularly to a laser system for illuminating a
giant column of air which is capable of assisting in the vertical
launching and landing of aircraft.
BACKGROUND OF THE INVENTION
Vertical take-off and landing (VTOL) aircraft are used in tactical
situations where extended runways are not available for
conventional jet fighters. This includes unimproved land areas and
ships smaller than aircraft carriers.
The typical VTOL aircraft must have power capacity greatly in
excess of that required for flying. This is due to the fact that
the VTOL aircraft requires high power to vertically take off and
land. This excess power requirement results in a heavier aircraft
which comprises optimum performance and efficiency
characteristics.
In my co-pending U.S. patent application Ser. No. 855,285, the
structure and method for permitting vertical take off and landing
of aircraft, including supersonic fighter aircraft on a smaller
ship, are provided. This avoids the necessity of providing a fleet
with expensive and specialized VTOL aircraft which cannot achieve
the performance and efficiency standards of regular supersonic
aircraft.
In accordance with the co-pending invention, means are provided for
generating an air column above the deck of a ship which has a
bucket-shaped pressure ridge on the top of the column having the
capability of "capturing" an aircraft which enters the column in a
"deep stall" condition. The air column is then controlled to gently
lower the aircraft to the deck of a ship.
In order to vertically take off, the column of air is used to raise
the aircraft to a point well above the ship deck. The aircraft can
then quickly depart from the air column by entering a full thrust
condition.
By equipping smaller ships, such as destroyers, with the necessary
means for generating an air column, conventional supersonic
aircraft may be used instead of costly and less-efficient VTOL.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
The present invention is directed to a laser system for
illuminating the column of air which captures an aircraft thereby
enabling a pilot to see the air column and "bucket" during take-off
and landing.
Illumination of the air column is achieved by salting the column
and employing a laser operating at a frequency resonant with the
salt crytals. In the event the laser is to operate in the
non-visible spectrum, a laser imager may be installed in the
aircraft to display the illuminated column on a cockpit or head-up
display.
The above-mentioned objects and advantages of the present invention
will be more clearly understood when considered in conjunction with
the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a diagrammatic perspective view of a ship equipped with
the present invention;
FIG. 2 is a diagrammatic end view of the ship as illustrated in
FIG. 1;
FIG. 3 is a block diagram of various means for powering a giant fan
which creates the air column as utilized in the present
invention;
FIG. 4 is a block diagram of a servo mechanism for controlling the
position of louvers as employed in the present invention;
FIG. 5 is a diagrammatic illustration of a land-based system for
generating an air column in accordance with the present
invention.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
FIG. 1 illustrates the basic concept of my referenced co-pending
application and the present invention. A relatively small ship,
such as destroyer 18, has its aft deck 14 equipped with the
vertical take-off and landing apparatus of the co-pending
application, generally illustrated by reference numeral 10. The
apparatus includes two side-by-side giant fans 12 located below the
deck at the stern 16 of the ship. Although two fans are
illustrated, the number will depend upon the type of aircraft
handled as well as the size of the ship.
A plurality of movable deck louvers 24 are mounted over the fans;
and as partially shown in FIG. 2, a grill 25 may cover the top of
the louvers to provide a support for aircraft. The sides 20 of the
ship include air supply vents 22 which may be covered when not in
use. When the fans 12 are operated, air is swept in through the
vents 22 and deflected by the louvers 24 to form an air column 26.
The column is sufficiently high to permit an aircraft 30, sitting
atop the column of air to enter a full thrust condition and obtain
sufficient air speed for flight before hitting the water. Since the
air velocity at the tip sections of each fan is greater than that
at the hub, column 26 forms a pressure bucket 28 which tends to
center a "captured" aircraft 30 on the column.
During vertical landing, as an aircraft 30 approaches column 26, it
may achieve "deep stall" by moving its horizontal stabilizers 32
and 33 to a downward vertical position. In this "deep stall," the
aircraft 30 descends into and is cradled by the bucket 28. The
aircraft may be lowered onto the grid 25 (FIG. 2) by decreasing the
velocity of the fans 12 to apply decreasing pressure to the
underside of the aircraft.
By slowly diminishing the pressure exerted by the air column on the
aircraft while still maintaining bucket 28, the aircraft 30 is
gently lowered for landing. The optimum position for the air column
26 exists when it is substantially perpendicular to the wing plane
of aircraft 30. This can be accomplished by operating the louvers
in one of the following ways: vectoring; pendulum operated;
gyroscopically operated; or dynamically connected to conventional
movable roll fins 29. Movable roll fins 29 are provided on the ship
sides 20, below the water line, to prevent possible sinking of the
bow 16 and to add critical stability to the ship 18. The movable
roll fins are also employed to maintain ship roll at a maximum of
approximately 30.degree.. The fins or other shipboard roll control
devices are not, per se, part of the present invention. Although
they are desirable they are not necessary for operation of the
present invention. The louvers may be controlled so that air column
26 is steered to be substantially perpendicular to the wing plane
of the aircraft in the presence of ship roll.
The procedure for vertical take-off is the reverse of that of
landing. An aircraft is initially located above grid 25 on the aft
deck section. The fans then slowly increase the height of the
column 26 while maintaining bucket 28 so that the aircraft 30
gradually attains an elevated position relative to the deck of the
ship. The horizontal stabilizers 32 and 33 are positioned to a
"deep stall" condition and the aircraft enters a full thrust
condition. This causes the aircraft to leave the column and slowly
dive toward the surface of the water. However, with sufficient air
column height, the aircraft will gain adequate air speed to allow
it to gain altitude before contacting the water surface.
A servo mechanism for varying louver position in the presence of
ship roll is shown in FIG. 4. A conventional roll sensor 21
generates an electrical signal to a servo motor 23 in accordance
with the degree of ship roll. The servo motor 23 has a shaft 27
which rotates the mechanically linked louvers 24 to an appropriate
offsetting position. As will be appreciated, the angles of the
louvers are adjusted to steer an aircraft during landing or
take-off in a manner which will compensate for roll of the
ship.
FIG. 3 illustrates a variety of means for powering the fans 12 from
shipboard power sources. In a preferred embodiment of the
invention, plentiful steam from boiler 31 provides the energy for
powering the fans 12 through a variable control valve 43. The steam
may power a turbine 35 which has its output shaft connected to
shaft 41 of fan 12. Preferably, the turbine 35 would be located
under the louvers 24 in order to make power transmission most
efficient. If space prohibits this, the turbine 35 may alternately
drive generator 37 which in turn powers motors 39. The motor 39 may
drive a respective fan 12. It is also possible to eliminate use of
the fan and instead direct steam from boiler 31 or another
shipboard source of gas or steam through ducts 29' so that the
steam is directed through louvers 24, thereby resulting in an air
column such as 26 (FIG. 1). Although this last-discussed system
would have a greater energy efficiency than by using the fans, it
would require more complex and elaborate control in order to
achieve the "bucket" 28 at the top of the air column. By using a
steam adjustment device such as valve 43, the energy for creating
the air column 26 may be controlled in a variable manner to enable
the height of an air column to be slowly and precisely varied to
enable gentle raising and lowering of an aircraft.
For shipboard use, it would be desirable to steer the ship downwind
so that deck wind is avoided and turbulence caused by motion of the
ship superstructure 34 is mimimized. Vertical take-off and landing
is preferably done athwart ship or sideways to the length of the
ship, thereby minimizing collision mishaps with the superstructure
34 of the ship.
Although the co-pending application deals with shipboard use, it is
equally applicable for land installation where a sufficient runway
is not present. FIG. 5 illustrates the structure necessary for
accomplishing such a land-based system. A plurality of jet engines
44 are employed to generate sufficient airflow to form an air
column 26. A louvered structure 36 having individual louvers 38 may
be constructed above ground with openings to admit airflow from the
jet engines 44. Curved baffles 46 are incorporated inbetween the
louvers to deflect the airflow from the jet engines 44 to a
vertically upward air column 26. The top of the louvered structure
is covered with a grid 42 to permit an aircraft to rest atop the
structure.
During take-off, an aircraft is moved by a crane 48 to a hoisted
position over the louvers. Then, the jet engines 44 are activated
and the column of air 26 can elevate the aircraft to a higher
position while the crane is withdrawn in preparation of a full
thrust take-off. In a reverse fashion, after a plane has landed on
the louvered structure, the crane 48 moves it to an adjacent ground
position off the louvered structure.
In a land-based system illustrated in FIG. 5, it is necessary to
control the delivery of the air from the jet engines to the louvers
in a manner that will ensure the presence of a "bucket" 28 atop the
air column. This is accomplished by designing the plenums between
the louvers in a manner ensuring greater air velocity at the
periphery of the louvered structure 38 than at its hub so that an
equivalent air column configuration can be obtained as compared
with the air column created by fans.
In both the land-based and shipboard systems, it is preferable to
cover the top of the louvered structure when not in use, thereby
preventing damage to the interior of the structure.
In order to illuminate the column of air 26 and bucket 28 for a
pilot, the present invention offers a laser system. A source of
illumination is a laser 50 which is mounted atop ship structure 52.
In tactical seaboard operations, ship pilots are reluctant to
surround their vessel with visible light sources. Accordingly, the
laser 50 could be made to operate in the non-visible, infrared
range.
Normally, air and salt spray enter vents 22 so that air column 26
is seeded with salt spray. The laser source 50 is selected so that
its emitted light is resonant with the salt crystals in the salt
spray. By directing the laser beam 54 along air column 26, the salt
spray in the column will reflect light energy. In applications
where a lighted air column is of no consequence, a pilot aboard the
aircraft 30 may visibly sight the column in order to achieve
accurate take-off or landing of the aircraft. However, as
previously mentioned, in tactical situations at sea, it may be
necessary to select laser 50 to operate in the non-visible light
spectrum. Since the reflected light from a non-visible laser source
will also be non-visible, it is necessary to incorporate a laser
imager 56 into the aircraft 30 for detecting the non-visible
reflections of light from air column 26. This type of laser imager
may be of the type utilized in a number of armored vehicle and
missile weapon control systems existing at the present time. The
location of the imaged air column is presented to a pilot on a
conventional head-up or cockpit display 58 of the type installed
within fighter aircraft. The laser imager 56 is tuned to the
wavelength of reflected energy from the salted air column 26.
In operation of the system, laser 50 is turned on only during the
short periods for take-off and landing of aircraft so that enemy
detecting devices do not detect the presence of the ship.
Although the use of lasers to illuminate aircraft vortices in wind
tunnels has been previously accomplished, the present invention
offers a patentably distinct application for laser illumination of
airflow.
It should be understood that the invention is not limited to the
exact details of construction shown and described herein, for
obvious modifications will occur to persons skilled in the art.
* * * * *